MCQ Bank
Lactobacillus is a genus of Gram-positive which are
- A) facultative aerobic
- B) obligate aerobes
- C) Anaerobic
- D) aerobic
What is the purpose of using spreader in the spread plate method?
- A) Avoid contamination
- B) Reduce agar temperature
- C) Evenly distributed inoculum
- D) Enhance microbial growth
What is the primary role of lactic acid bacteria (LAB) in yoghurt production?
- A) Protein degradation
- B) Flavor enhancement
- C) Lactose fermentation
- D) Lipid synthesis
What is the significance of performing a five-fold serial dilution in the isolation of Aspergillus?
- A) Obtain pure cultures
- B) Enhance enzyme activity
- C) Increase sample volume
- D) Accelerate fermentation
Why is malt extract agar (MEA) used for isolating molds and yeasts from the fermenting gruel?
- A) Support bacterial growth
- B) Provide essential nutrients
- C) Inhibit fungal growth
- D) Enhance coloration
What role does diacetyl play in the selection of LAB colonies?
- A) Lactose fermentation
- B) Protein synthesis
- C) Sugar degradation
- D) Flavor production
What is the key aspect of a successful spread plate method?
- A) Rapid bacterial growth
- B) Minimal incubation time
- C) High agar temperature
- D) Even isolation of colonies
What is the primary role of Aspergillus sp. in traditional Japanese fermentation industries?
- A) Enzyme secretion
- B) Antibiotic production
- C) Lipid synthesis
- D) Protein degradation
After completing the serial dilution, what is used for inoculation on specific media?
- A) Distilled water
- B) Serial dilutions
- C) Sterile diluent
- D) Melted agar
What is the dilution factor labeled for the first test tube in the serial dilution process?
- A) 10-4
- B) 10-2
- C) 10-3
- D) 10-1
Why is checking agar plates for moisture crucial in the streak plate method?
- A) Improve agar texture
- B) Identify contamination
- C) Accelerate incubation
- D) Enhance microbial growth
Which health issues can be caused by Aspergillus species when their spores are inhaled?
- A) Gastrointestinal issues
- B) Respiratory issues
- C) Muscular dystrophy
- D) Cardiovascular diseases